A cartridge for a teatcup, and a teatcup

ABSTRACT

A cartridge and a teatcup to be attached to the teat of an animal to be milked are disclosed. The cartridge includes an elongated sleeve, having an upper end section and a lower end section, and a teatcup liner pre-mounted in the elongated sleeve. The teatcup liner includes an upper end portion located at the upper end section, a lower end portion located at the lower end section, and a barrel portion extending between the upper and lower end portions. The barrel portion has a polygonal cross-sectional shape defining a plurality of corner portions and a plurality of side portions. The elongated sleeve includes a primary locking member. The teatcup liner includes a primary complementary locking member. The two locking members engage each other to prevent rotation of the teatcup liner in relation to the elongated sleeve.

TECHNICAL FIELD OF THE INVENTION

The present invention refers to a cartridge according to the preamble ofclaim 1. The invention also refers to a teatcup comprising a cartridge.

BACKGROUND AND PRIOR ART

WO 2014/178783 discloses a teatcup comprising a connector and acartridge. The connector is associated with or comprises an outer shell.The teatcup is configured to be attached to the teat of an animal to bemilked. The cartridge comprises an elongated sleeve extending inparallel with a longitudinal central axis and has an upper end sectionand a lower end section. A teatcup liner is pre-mounted in the elongatedsleeve and has an inner space for receiving the teat. A pulsationchamber is formed between an inner side of the elongated sleeve and anouter side of the teatcup liner. The teatcup liner comprises an upperend portion located at the upper end section of the elongated sleeve, alower end portion located at the lower end section of the elongatedsleeve, and a barrel portion extending between the upper end portion andthe lower end portion.

When inserting the cartridge into a connector of the teatcup, and whenremoving the cartridge from the connector, it could happen that theteatcup liner is rotated in relation to the elongated sleeve when theinsertion and/or the removal includes a rotary movement. The teatcupliner may then be twisted, which significantly decreases the performanceof the teatcup liner. This is in particular a problem, when the barrelportion of the teatcup liner at least in a rest state has a polygonalcross-sectional shape defining a plurality of corner portions and aplurality of side portions, each connecting two of said corner portions.Such polygonal teatcup liners are very sensible to twisting.

SUMMARY OF THE INVENTION

The object of the present invention is to remedy the problems discussedabove, and to provide an improved cartridge for a teatcup. Inparticular, it is aimed at a cartridge in which twisting of the teatcupliner in relation to the elongated sleeve can be avoided.

This object is achieved by the cartridge initially defined, which ischaracterized in that the barrel portion in a rest state has a polygonalcross-sectional shape defining a plurality of corner portions and aplurality of side portions, each connecting two of said corner portions,that the elongated sleeve comprises a primary locking member, that theteatcup liner comprises a primary complementary locking member, and thatthe primary locking member and the primary complementary locking memberengage each other to prevent rotation of the teatcup liner in relationto the elongated sleeve around the longitudinal central axis.

The primary locking member and the primary complementary locking membermay thus interact to lock the rotary position of the teatcup liner inthe elongated sleeve, and prevent any twisting of the teatcup liner evenif the cartridge would be rotated when it is inserted in the teacup orremoved from the teatcup.

Moreover, the primary locking member and the primary complementarylocking member define the rotary position of the teatcup liner in theelongated sleeve. Thus, the teatcup liner may be fixed in one singlerotary position in the elongated sleeve.

Twisting of the teatcup liner may thus be prevented even if thecartridge is rotated during insertion into or removal from the connectorof the teatcup.

According to to an embodiment of the invention, the elongated sleevecomprises a plurality of openings, each being provided opposite to arespective one of the side portions of the teatcup liner and eachpermitting passage of a pulsating pressure into and out from thepulsation chamber.

This positioning of the openings in relation to the teatcup liner isensured and defined by means of the primary locking member and theprimary complementary locking member.

Since an opening is provided opposite to each side portion, where thedistance to the inner side of the elongated sleeve is longest, a properflow of the air of the pulsation pressure is achieved.

According to an embodiment of the invention, the openings extend throughthe lower end section of the elongated sleeve.

According to an embodiment of the invention, the openings areequidistantly distributed around the lower end section of the elongatedsleeve.

According to an embodiment of the invention, the barrel portioncomprises a protruding ring projecting outwardly and extending aroundthe barrel portion in the proximity of the lower end portion, whereinthe protruding ring comprises a plurality of straightened portions.

Such protruding ring, which may be a result of the manufacturing processof the teatcup liner, may obstruct the flow of air of the pulsationpressure. By positioning the openings opposite to the straightenedportions, where the distance to the inner side of the elongated sleeveis longest, the proper flow of the air may be ensured.

According to an embodiment of the invention, the lower end portion ofthe teatcup liner comprises an annular flange extending outwardly,wherein the annular flange abuts an end surface of the lower end sectionof the elongated sleeve.

According to an embodiment of the invention, the openings are locatedaxially between the protruding ring and the annular flange.

According to an embodiment of the invention, the lower end portion ofthe teatcup liner comprises an end nozzle extending beyond the lower endsection of the elongated sleeve and having a circumferential externalsurface configured to abut a seal surface of the connector of theteatcup.

Thanks to the primary locking member and the primary complementarylocking member, twisting of the teatcup liner is prevented even thenwhen the cartridge upon removal from the connector is rotated inrelation to the connector, and especially when the end nozzle isabutting the seal surface of the connector.

According to an embodiment of the invention, the barrel portion is madeof a first material and the lower end portion is made of a secondmaterial, wherein the second material has a high rigidity in comparisonwith the first material.

According to an embodiment of the invention, the primary locking memberis located at the lower end section of the elongated sleeve, wherein theprimary complementary locking member is provided on the lower endportion of the teatcup liner.

According to an embodiment of the invention, the primary complementarylocking member is provided on the annular flange.

The annular flange is of the second material with the relatively highrigidity, which ensure a secure mutual engagement of the primary lockingmember and the primary complementary locking member.

According to an embodiment of the invention, the primary complementarylocking member comprises a recess in the annular flange, wherein theprimary locking member comprises a protrusion extending from the lowerend section of the elongated sleeve into the recess of the primarycomplementary locking member.

The protrusion may be securely engaged in the recess.

According to an embodiment of the invention, the cartridge comprises alip member attachable or attached to the upper end portion of theteatcup liner, thereby securing the lip member to the upper end portionof the teatcup liner in an axial direction.

According to an embodiment of the invention, the lip member comprises asecondary locking member, and the elongated sleeve comprises a secondarycomplementary locking member, wherein the secondary locking member andthe secondary complementary locking member engage each other to preventrotation of the lip member in relation to the elongated sleeve and tothe teatcup liner around the longitudinal central axis.

Also the secondary locking member and the secondary complementarylocking member contributes to ensure the rotary position of the teatcupliner in the elongated sleeve, and thus to prevent twisting of theteatcup liner in relation to the elongated sleeve.

According to an embodiment of the invention, the secondary complementarylocking member comprises at least one recess in an annular flangeextending outwardly at the upper end section of the elongated sleeve,wherein the secondary locking member comprises at least one protrusionextending downwardly from a lower end of the lip member into arespective recess of the secondary complementary locking member.

The protrusions may be securely engaged in a respective one of therecesses.

The object is also achieved by the teatcup initially defined, whichcomprises a connecter and a cartridge as defined above.

The connector may comprise an outer shell, wherein the cartridge isinsertable into the connector with the outer shell to form the teatcup.

The primary locking member and the primary complementary locking membermay thus interact to lock the rotary position of the teatcup liner inthe elongated sleeve, and prevent any twisting of the teatcup liner evenif the cartridge would be rotated when it is inserted in the teacup orremoved from the teatcup.

According to an embodiment of the invention, the lower end portion ofthe teatcup liner comprises an end nozzle extending beyond the lower endsection of the elongated sleeve and having a circumferential externalsurface configured to abut a seal surface of the connector of theteatcup.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be explained more closely by means of adescription of various embodiments and with reference to the drawingsattached hereto.

FIG. 1 discloses an exploded perspective view of a teatcup according toan embodiment of the invention.

FIG. 2 discloses a longitudinal sectional view of the teatcup in FIG. 1.

FIG. 3 discloses a perspective view from above of a connector of theteatcup in FIG. 1.

FIG. 4 discloses a perspective view from above of a cartridge of theteatcup in FIG. 1.

FIG. 5 discloses a perspective view from below of the cartridge in FIG.4.

FIG. 6 discloses a longitudinal sectional view of a lower part of theteatcup in FIG. 1.

FIG. 7 discloses a cross-sectional view along the line VII-VII in FIG.6.

FIG. 8 discloses a perspective view from below of a lower part of anelongated sleeve of the cartridge in FIG. 4.

FIG. 9 discloses a perspective view from above of a lower part of ateatcup liner of the cartridge in FIG. 4.

FIG. 10 discloses a perspective view from below of a lower part of thecartridge in FIG. 4.

FIG. 11 discloses a perspective exploded view from below a lip memberand an upper part of the cartridge in FIG. 4.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

FIGS. 1 and 2 disclose a teatcup to be attached to the teat of an animalto be milked. The teatcup comprises a cartridge 1, a connector 2. Theconnector 2 comprises or is associated with an outer shell 3. The outershell 3 may be an integrated part of the connector 2.

In the following, the word “upper” refer to any part being closest tothe teat and the udder of the animal during milking, and the word“lower” to any part being most remote from the teat and the udder duringmilking.

The teatcup may comprise or be connected to a milk conduit 4, such as ashort milk conduit or a long milk conduit, and to a pulse conduit 5.

A longitudinal central axis x extends through and along the teatcup,i.e. through the cartridge 1 and the connector 2. The longitudinalcentral axis x may also extend through and along a part of the milkconduit 4 when it is in a rest state as partly indicated in FIG. 2.

The connector 2 comprises three heel members 6, which are providedcircumferentially after each other on an upper inner surface 7 of theconnector 2, see in particular FIG. 3, in which two of the heel members6 are visible. The heel members 6 are equidistantly distributed aroundthe longitudinal central axis x.

The heel members 6 project from the upper inner surface 7 towards thelongitudinal central axis x. Each heel member 6 has a rectangular shapewhen seen in a radial direction. Each heel member 6 has a main surface8, which may extend parallel with the upper inner surface 7. The mainsurface 8 is circular cylindrical, or substantially circularcylindrical.

Moreover, each heel member 6 has an upper side surface 9 and a lowerside surface 10. The upper and lower side surfaces 9 and 10 may extendperpendicularly between the main surface 8 and the upper inner surface7, and thus in parallel with each other.

A chamfer may be provided at the transition between the upper surface 9and the main surface 8.

The connector 2 comprises an upper outer surface 11 opposite to theupper inner surface 7. The upper outer surface 11 extends from an upperend of the connector 2 and ends at a shoulder 12. The upper outersurface 11 is circular cylindrical, or substantially circularcylindrical.

The outer shell 3 is provided onto the upper outer surface 11 of theconnector 2, as can be seen in FIG. 2, so that the connector 2 and theouter shell 3 form a unit. For instance, the outer shell 3 may bepress-fitted onto the upper outer surface 11. A lower end of the outershell 3 abuts the shoulder 12.

The connector 2 comprises a flange 13 extending inwardly towards thelongitudinal central axis x, especially radially inwardly. The flange 13may be provided at the bottom end of the connector 2. The flange 13 mayengage a corresponding groove 14 in an upper portion 15 of the milkconduit 4 in order to releasably attach the connector 2 to the milkconduit 4 as can be seen in FIGS. 2 and 6.

The upper portion 15 of the milk conduit 4 is at least partly located ina closed space 16 formed by and between the connector 2 and thecartridge 1, see FIGS. 2 and 6.

The upper portion 15 of the milk conduit 4 also forms a seal surface 17,which is annular and tapers downwardly as can be seen in FIGS. 2 and 6.The seal surface 17 is to be explained below.

Furthermore, the connector 2 comprises a pulse nipple 18 forming acommunication channel to the closed space 16. The pulse nipple 18 isconnected to the pulse conduit 5. The pulse nipple 18 extends downwardlyfrom the connector 2.

The cartridge 1, see also FIGS. 4 and 5, comprises an elongated sleeve20 and a teatcup liner 21, which is pre-mounted in the elongated sleeve20 and has an inner space 22 for receiving the teat.

The elongated sleeve 20 extends in parallel with the longitudinalcentral axis x and has an upper end section 20 a and a lower end section20 b.

The teatcup liner 21 comprises an upper end portion 21 a located at theupper end section 20 a of the elongated sleeve 20, a lower end portion21 b located at the lower end section 20 b of the elongated sleeve 20,and a barrel portion 21 c extending between the upper end portion 21 aand the lower end portion 21 b.

The cartridge 1 also comprises a pulsation chamber 23, which is formedor enclosed between an inner side of the elongated sleeve 20 and anouter side of the teatcup liner 21, see FIG. 2.

Furthermore, the cartridge 1 comprises a lip member 24, which isattachable or attached to the upper end portion 21 a of the teatcupliner 21 by means of a snap connection 24 b, see FIG. 2. The lip member24 comprises a lip 24 a, which defines an opening through which the teatis introduced into the inner space 22 of the teatcup liner 21. Whenattached to the upper end portion 21 a, the lip member 24 is securelyconnected to the upper end portion 21 a of the teatcup liner 21 in anaxial direction.

In the embodiment disclosed, the barrel portion 21 c has, in a reststate, a triangular cross-sectional shape defining three corner portions25 and three side portions 26. Each side portion 26 is straightened andextends between and connects two of the three corner portion 25, seeFIGS. 2, 7 and 9.

It should be noted, that the barrel portion 21 c in principle may haveany polygonal cross-sectional shape, for instance a square or apentagonal cross-sectional shape.

The lower end portion 21 b of the teatcup liner 21 comprises an annularflange 27 extending outwardly, see FIG. 6. The annular flange 27 abutsan end surface of the lower end section 20 b of the elongated sleeve 20,and maintains the axial position of the lower end portion 21 b inrelation to the elongated sleeve 20.

The barrel portion 21 c of the teatcup liner 21 is made of a firstmaterial and the lower end portion 21 b of the teatcup liner 21 is madeof a second material. The second material has a high rigidity incomparison with the first material. The first material may consist of orcomprise rubber, black rubber, silicone rubber, elastic polymers, suchas Thermoplastic Elastomers, TPE, or any other suitable elasticmaterial. The second material may consist of or comprise a suitablepolymer with low elasticity, such as polyeten, polypropene, etc.

In order to prevent the teatcup liner 21 from being twisted in theelongated sleeve 20, the elongated sleeve 20 comprises a primary lockingmember 28, see FIG. 8, and the teatcup liner 21 a primary complementarylocking member 29, see FIG. 9.

The primary locking member 28 is located at the lower end section 20 bof the elongated sleeve 20. More precisely, the primary locking member28 comprises a protrusion which extends downwardly from the end surfaceof the lower end section 20 b. The primary locking member 28 may have adovetail shape, as can be seen in FIG. 8.

The primary complementary locking member 29 is provided on the lower endportion 21 b of the teatcup liner 21. More precisely, the primarycomplementary locking member 29 is provided on the annular flange 27.The primary complementary locking member 29 comprises or consists of arecess in the annular flange 27. The recess of the primary complementarymember 29 permits the protrusion of the primary locking member 28 to fitin the recess of the primary complementary locking member 29, when theteatcup liner 21 has been mounted in the elongated sleeve 20.

Thus, the primary locking member 28 and the primary complementarylocking member 29 engage each other, see FIGS. 8 and 9, to preventrotation of the teatcup liner 21 in relation to the elongated sleeve 20around the longitudinal central axis x.

Moreover, the primary locking member 28 and the primary complementarylocking member 29 define the rotary position of the teatcup liner 21 inthe elongated sleeve 20.

It should be noted that the primary locking member 28 and the primarycomplementary locking member 29 may comprise more than one protrusionand recess, respectively.

Additionally, twisting of the teatcup liner 21 in the elongated sleeve20, may be prevented by a secondary locking member 31 of the lip member24, and a secondary complementary locking member 32 of the elongatedsleeve 20, see FIGS. 4, 5 and 11.

The secondary locking member 31 comprises four protrusions 33 extendingdownwardly from a lower end of the lip member 24. The secondarycomplementary locking member 32 comprises four recesses 34 in an annularflange 35 extending outwardly at the upper end section 20 a of theelongated sleeve 20. The protrusions 33 are configured to interact withthe recesses 34 to prevent twisting or rotation of the teatcup liner 21in relation to the elongated sleeve 20. When the lip member 24 has beenattached to the teatcup liner 21, and when the teat cup liner 21 withthe lip member 24 has been introduced into the elongated sleeve 20, theprotrusions 33 of the secondary locking member 31 fit in a respectiveone of the recesses 34 of the secondary complementary locking member 32so that the teatcup liner 21 will be locked in a rotational direction inrelation to the elongated sleeve 20.

Thus, the secondary locking member 31 and the secondary complementarylocking member 32 engage each other to prevent rotation of the lipmember 24 in relation to the elongated sleeve 20, and thus in relationto the teatcup liner 21 around the longitudinal central axis x.

It should be noted that the secondary locking member 31 and thesecondary complementary locking member 32 may comprise less than four ormore than four protrusions 33 and recesses 34, respectively.

In the embodiment disclosed, the elongated sleeve 20 comprises threeopenings 40, see in particular FIG. 7. Each opening 40 is providedopposite to a respective one of the side portions 26 of the teatcupliner 21, see FIG. 2. Each opening 40 permits passage of a pulsatingpressure into and out from the pulsation chamber 23 via thecommunication channel of the pulse nipple 18 and the closed space 16.

The openings 40 extend through the lower end section 20 b of theelongated sleeve 20, and are equidistantly distributed around the lowerend section 20 b of the elongated sleeve 20.

It should be noted, that the number of openings 40 may be another thanthree. However, the number of openings 40 may preferably correspond tothe polygonal shape of the barrel portion 20, and thus be the same asthe number of side portions 26.

The barrel portion 21 c comprises a protruding ring 41 projectingoutwardly and extending around the barrel portion 21 c in the proximityof the lower end portion 21 b, see FIGS. 6 and 7. The protruding ring 41comprises three straightened portions 42. Each straightened portion 42is axially, or substantially axially, aligned with a respective one ofthe side portions 26.

The protruding ring 41 thus has a polygonal shape corresponding to thepolygonal shape of the barrel portion 21 c above the protruding ring 41.Each straightened portion 42 extends between two curved portions 43.

Each straightened portion 42 is located partly opposite to a respectiveone of the openings 40, as can be seen in FIGS. 6 and 7. Thus, theopenings 40 are located axially between the protruding ring 41 and theannular flange 27. One of the straightened portions 42 can be seenthrough one of the openings 40 in FIG. 10.

The elongated sleeve 20 comprises three separate primary hook members 50provided circumferentially after each other on an outer surface 49 ofthe elongated sleeve 20, see FIGS. 1, 4-6, 8 and 10. The primary hookmembers 50 are equidistantly located after each other. The primary hookmember 50 are located at the same axial position.

The outer surface 49 is in the embodiment disclosed tapering from theupper end section 20 a to the lower end section 20 b.

Each of the primary hook members 50 has a lower slide surface 51 slopingupwardly and outwardly, and a upper hook surface 52 extending inwardly,see FIG. 6. The upper hook surface 52 may extend radially, orsubstantially radially, with respect to the longitudinal central axis x.

Each of the primary hook members 50 is configured to interact with arespective one of the heel members 6. The primary hook members 50 andthe heel members 6 define a primary rotary position of the cartridge 1in relation to the connecter 2 when each of the primary hook member 50is aligned with a respective one of the heel members 6.

When being in the primary rotary position, the cartridge 1 is insertablealong the longitudinal central axis x into the connector 2. During theintroduction of the cartridge 1, the lower slide surface 51 will slideon the heel member 6, especially on the chamfer between the uppersurface 9 and the main surface 8, until the heel member 6 passes thelower slide surface 51 of the primary hook member 50. The primary hookmember 50 will then snap outwardly so that the hook surface 52 of theprimary hook member 50 abuts and is engaged by the lower surface 10 ofthe heel member 6, see FIG. 2. From this inserted position, thecartridge 1 cannot be removed from the connector 2 by being pulled in anopposite direction along the longitudinal central axis x.

Moreover, the elongated sleeve 20 comprises three separate passages 58provided circumferentially after each other on the outer surface 49 ofthe elongated sleeve 20, see FIGS. 4, 5 and 10. The primary hook members50 and the passages 58 are thus provided after each other in analternating order around the outer surface 49 of the elongated sleeve20. Also the passages 58 are thus equidistantly distributed after eachother.

The elongated sleeve 20 also comprises a respective secondary hookmember 60 in two of the passages 58, see FIGS. 1 and 4.

Thus, two of the three passages 58 comprises a secondary hook member,see FIG. 10, whereas the third passage 58 has no secondary hook member,see FIG. 8.

Each of the secondary hook members 60 comprises a lower hook surface 61extending inwardly, and an upper slide surface 62 sloping upwardly andinwardly.

The two secondary hook members 60 are thus configured to interact with arespective one of two of the three heel members 6 to prevent thecartridge 1 from being inserted when the cartridge 1 is not in theprimary rotary position. When not in the primary rotary position, thelower hook surface 61 of two of the secondary hook members 60 willengage a respective one of the upper sides 9 of the two of the heelmembers 6, and thus prevent any further insertion of the cartridge 1into the connector 2.

In the embodiment disclosed, the elongated sleeve 20 comprises threestop members 64 projecting outwardly from the outer surface 49. Eachstop member 64 has an elongated shape and extends axially. Each stopmember 64 is provided adjacent to and axially above a respective one ofthe primary hook members 50.

When the cartridge 1 is in the inserted position in the connector 2, thestop members 64 will interact with the heel members 6 to permit thecartridge 1 to be rotated around the longitudinal central axis x inrelation to the connector 1 in a primary direction from the primaryrotary position to a secondary rotary position.

In the secondary rotary position, each passage 58 is axially alignedwith a respective one of the heel members 6, and the cartridge 1 isremovable from the connector 2. The cartridge 1 is in this secondaryrotary position movable upwardly along the longitudinal central axis xin relation to the connector 2, wherein the heel members 6 will guidedover a respective one of the passages 58. This guiding of the heelmembers 6 through the passages 58 is facilitated thanks to the fact thatone of the passages 58, see FIG. 8, lacks a secondary hook member 60.

Furthermore, the stop members 64 will interact with the heel members 6to prevent the cartridge 1 from being rotated in a secondary direction,opposite to the primary direction, from the primary rotary position to asecondary rotary position.

In the embodiment disclosed the elongated sleeve 20 comprises threesurface areas 66. Each surface area 66 has a circular cylindricalextension and is provided above a respective one of the primary hookmembers 50. When the cartridge 1 is in the inserted position in theconnector 2, each surface area 66 will be opposite to the main surface 8of a respective one of the heel members 6. Above the surface area 66, asloping area 67 is provided, which slopes upwardly and outwardly andconnects the surface area 66 to the outer surface 49.

Each stop member 64 is provided between one of the surface areas 66 andone of the passages 58.

In the embodiment disclosed, the elongated sleeve 20 comprises three ribmembers 68 extending outwardly from the outer surface 49. Each ribmember 68 has an elongated shape and extends axially. Each rib member 68is provided adjacent to and axially above a respective one of theprimary hook members 50. The rib members 68 has a lower height from thesurface areas 66 than the stop members 64 to permit the heel members 6to be guided over the rib members 68 when being rotated in any directionbetween the primary rotary position and the secondary rotary position.Each rib member 68 is provided between one of the passages 58 and one ofthe surface areas 66.

In the embodiment disclosed, the elongated sleeve 20 comprises a sealmember 70 which extends around the outer surface 49 of the elongatedsleeve 20. The seal member 70 is provided in circumferential groove 71in the outer surface 49 of the elongated sleeve 20. The circumferentialgroove 71 is provided axially between the openings 40 and the primaryhook members 50. The seal member 70 abuts a lower inner surface 75 ofthe connector 2 and seals the closed space 16 when the cartridge 1 is inthe inserted position, see FIGS. 2, 3 and 6.

In the embodiment disclosed, the lower end portion 21 b of the teatcupliner 21 comprises an end nozzle 72 extending beyond the lower endsection 20 b of the elongated sleeve 20. The end nozzle 72 has acircumferential external surface 73 which abuts the seal surface 17 ofthe upper portion 15 of the milk conduit 4 when the cartridge 1 is inthe inserted position in the connector 2, and when the primary hooksmembers 50 are engaged by the heel members 6, see FIG. 2.

In the teatcup disclosed, the cartridge 1 may easily be replaced. Theoperator then grips the teatcup and rotates the cartridge 1 from theprimary rotary position to the secondary rotary position by gripping thelip member 24 of the cartridge 1 and rotating it I relation to theconnector 2 and the outer shell 3.

Thanks to the primary locking member and the primary complementarylocking member 28, 29, and to the secondary locking member and thesecondary complementary locking member 31, 32, the teatcup liner willremain in the same rotary position in relation to the elongated sleeve21, and thus not be twisted.

In the secondary rotary position, the cartridge 1 may then be pulled outof the connector 2 and the outer shell 3, by pulling the lip member 24along the longitudinal central axis x in relation to the connector 2 andthe outer shell 3.

A new cartridge 1 may then be inserted into the connector 2 and theouter shell 3. During the insertion, the cartridge 1 is positioned sothat the heel members 6 are aligned with the primary hook members 50,i.e. to the primary rotary position. The cartridge 1 is pushed furthervia the lip member 24 into the outer shell 3 and the connector 2 untilthe primary hook members 50 snaps into engagement with the heel members6. The rotation of the cartridge 1 is made before the end nozzle 72 hasreached the seal surface 17, and thus no twisting forces can be exertedon the teatcup liner 21.

The present invention is not limited to the embodiments disclosed, butmay be varied and modified within the scope of the following claims.

1. A cartridge configured to form a part of a teatcup including aconnector, the teatcup being configured to be attached to a teat of ananimal to be milked, the cartridge comprising: an elongated sleeveextending in parallel with a longitudinal central axis and having anupper end section and a lower end section, the elongated sleevecomprising a primary locking member that is a protrusion extendingdownwardly from the lower end section of the elongated sleeve; a teatcupliner pre-mounted in the elongated sleeve and having an inner space forreceiving said teat, the teatcup liner comprising an upper end portionlocated at the upper end section of the elongated sleeve, a lower endportion located at the lower end section of the elongated sleeve, abarrel portion extending between the upper end portion and the lower endportion, the barrel portion in a rest state having a polygonalcross-sectional shape defining a plurality of corner portions and aplurality of side portions each connecting two of said corner portions,and a primary complementary locking member defined in the lower endportion of the teatcup liner and configured to receive the protrusiontherein; and a pulsation chamber between an inner side of the elongatedsleeve and an outer side of the teatcup liner, wherein the primarylocking member and the primary complementary locking member engage eachother to prevent rotation of the teatcup liner in relation to theelongated sleeve around the longitudinal central axis.
 2. The cartridgeaccording to claim 1, wherein the elongated sleeve comprises a pluralityof openings, each of the plurality of openings being provided oppositeto a respective one of the side portions of the teatcup liner and eachof the plurality of openings permitting passage of a pulsating pressureinto and out from the pulsation chamber.
 3. The cartridge according toclaim 2, wherein the openings extend through the lower end section ofthe elongated sleeve.
 4. The cartridge according to claim 3, wherein theopenings are equidistantly distributed around the lower end section ofthe elongated sleeve.
 5. The cartridge according to claim 4, wherein thebarrel portion comprises a protruding ring projecting outwardly andextending around the barrel portion in the proximity of the lower endportion, the protruding ring comprising a plurality of straightenedportions.
 6. The cartridge according to claim 1, wherein the lower endportion of the teatcup liner comprises an annular flange extendingoutwardly, the annular flange abutting an end surface of the lower endsection of the elongated sleeve.
 7. The cartridge according to claim 6,wherein the openings are located axially between the protruding ring andthe annular flange.
 8. The cartridge according to claim 1, wherein thelower end portion of the teatcup liner comprises an end nozzle extendingbeyond the lower end section of the elongated sleeve and having acircumferential external surface configured to abut a seal surface ofthe connector of the teatcup.
 9. The cartridge according to claim 1,wherein the barrel portion is made of a first material and the lower endportion is made of a second material, and wherein the second materialhas a relatively high rigidity in comparison with the first material.10. The cartridge according to claim 1, wherein the primary lockingmember is located at the lower end section of the elongated sleeve, andwherein the primary complementary locking member is provided on thelower end portion of the teatcup liner.
 11. The cartridge according toclaim 6, wherein the primary complementary locking member is provided onthe annular flange.
 12. The cartridge according to claim 11, wherein theprimary complementary locking member comprises a recess in the annularflange, and wherein the protrusion extends from the lower end section ofthe elongated sleeve into the recess of the primary complementarylocking member.
 13. The cartridge according to claim 1, furthercomprising a lip member attachable to the upper end portion of theteatcup liner, thereby securing the lip member to the upper end portionof the teatcup liner in an axial direction.
 14. The cartridge accordingto claim 13, wherein the lip member comprises a secondary lockingmember, and the elongated sleeve comprises a secondary complementarylocking member, and wherein the secondary locking member and thesecondary complementary locking member engage each other to preventrotation of the lip member in relation to the elongated sleeve and tothe teatcup liner around the longitudinal central axis.
 15. Thecartridge according to claim 14, wherein the secondary complementarylocking member comprises at least one recess in an annular flangeextending outwardly at the upper end section of the elongated sleeve,and wherein the secondary locking member comprises at least oneprotrusion extending downwardly from a lower end of the lip member intoa respective recess of the secondary complementary locking member.
 16. Ateatcup comprising: the connecter; and the cartridge according toclaim
 1. 17. The cartridge according to claim 1, wherein the primarycomplementary locking member comprises a recess in the annular flange,and the primary locking member has a dovetail shape to engage with therecess of the primary complementary locking member.
 18. A cartridgeconfigured to form a part of a teatcup including a connector, theteatcup being configured to be attached to a teat of an animal to bemilked, the cartridge comprising: an elongated sleeve extending inparallel with a longitudinal central axis and having an upper endsection and a lower end section, the elongated sleeve comprising aprimary locking member that is a protrusion extending downwardly fromthe lower end section of the elongated sleeve; and a teatcup linerpre-mounted in the elongated sleeve and having an inner space forreceiving said teat, the teatcup liner comprising an upper end portionlocated at the upper end section of the elongated sleeve, a lower endportion located at the lower end section of the elongated sleeve, abarrel portion extending between the upper end portion and the lower endportion, and a primary complementary locking member defined in the lowerend portion of the teatcup liner and configured to receive theprotrusion therein, wherein the primary locking member and the primarycomplementary locking member engage each other to prevent rotation ofthe teatcup liner in relation to the elongated sleeve around thelongitudinal central axis.
 19. The cartridge according to claim 18,wherein the barrel portion in a rest state has a polygonalcross-sectional shape defining a plurality of corner portions and aplurality of side portions each connecting two of said corner portions.20. A cartridge configured to form a part of a teatcup including aconnector, the teatcup being configured to be attached to a teat of ananimal to be milked, the cartridge comprising: an elongated sleeveextending in parallel with a longitudinal central axis and having anupper end section and a lower end section, the elongated sleevecomprising a primary locking member and a plurality of openings; ateatcup liner pre-mounted in the elongated sleeve and having an innerspace for receiving said teat, the teatcup liner comprising an upper endportion located at the upper end section of the elongated sleeve, alower end portion located at the lower end section of the elongatedsleeve, a barrel portion extending between the upper end portion and thelower end portion, the barrel portion in a rest state having a polygonalcross-sectional shape defining a plurality of corner portions and aplurality of side portions each connecting two of said corner portions,and a primary complementary locking member; and a pulsation chamberbetween an inner side of the elongated sleeve and an outer side of theteatcup liner, wherein the primary locking member and the primarycomplementary locking member engage each other to prevent rotation ofthe teatcup liner in relation to the elongated sleeve around thelongitudinal central axis, and each of the plurality of openings isprovided opposite to a respective one of the side portions of theteatcup liner and each of the plurality of openings permitting passageof a pulsating pressure into and out from the pulsation chamber.